

A080710


a(0) = 1; for n>0, a(n) is taken to be the smallest positive integer greater than a(n1) which is consistent with the condition "n is a member of the sequence if and only if a(n) is a multiple of 3".


4



1, 3, 4, 6, 9, 10, 12, 13, 14, 15, 18, 19, 21, 24, 27, 30, 31, 32, 33, 36, 37, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 51, 54, 57, 58, 59, 60, 63, 64, 66, 69, 72, 75, 78, 81, 84, 87, 90, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 105, 108, 111, 112, 113, 114, 117, 118, 120
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OFFSET

0,2


COMMENTS

Is this the same sequence as A115837?  Andrew S. Plewe, May 08 2007


LINKS

Table of n, a(n) for n=0..66.
B. Cloitre, N. J. A. Sloane and M. J. Vandermast, Numerical analogues of Aronson's sequence, J. Integer Seqs., Vol. 6 (2003), #03.2.2.
B. Cloitre, N. J. A. Sloane and M. J. Vandermast, Numerical analogues of Aronson's sequence (math.NT/0305308)
Index entries for sequences of the a(a(n)) = 2n family


FORMULA

a(a(n)) = 3*(n+1).


PROG

(PARI) {a=1; m=[1]; for(n=1, 67, print1(a, ", "); a=a+1; if(m[1]==n, while(a%3>0, a++); m=if(length(m)==1, [], vecextract(m, "2.."))); m=concat(m, a))}


CROSSREFS

Cf. A003605, A079253, A080711, A080712.
Cf. A079000, A003605, A079253, A080711, A080712.
Sequence in context: A190899 A173671 A325440 * A115837 A102342 A286692
Adjacent sequences: A080707 A080708 A080709 * A080711 A080712 A080713


KEYWORD

nonn,easy


AUTHOR

N. J. A. Sloane, Mar 05 2003


EXTENSIONS

More terms and PARI code from Klaus Brockhaus, Mar 06 2003


STATUS

approved



